The present invention relates to a method for clutch disengagement at idle engine speed driving of a vehicle comprising an automated manual transmission.
The present invention further relates to a clutch disengagement controller controlling a rate of clutch disengagement at engine idling running mode. The clutch disengagement controller is connected to a brake pedal sensor sensing a force applied to a brake pedal and to at least one air inlet valve controlling a position of a clutch cylinder governing said clutch disengagement.
In vehicles utilizing automated manual transmission gearboxes, some manufacturers allow the vehicle to continue to run at engine idling speed at low gears, even if the accelerator pedal has been completely released. There is however a problem connected to this engine idling running, namely the disengagement of the clutch, which will occur upon pressing down a brake pedal in the vehicle. In prior art solutions, a clutch disengagement is always done in the same way, namely to disengage the clutch immediately after a brake pedal sensor has sensed a position change of the brake pedal. The clutch disengagement is always performed in the same way, which might lead to unsmooth vehicle stops if only a light pressure is applied to the brake pedal, and to unnecessary engine speed decreases if a high pressure is applied to the brake pedal.
According to the invention, the above problems are solved in that a rate of a clutch disengagement is controlled responsive to a brake pedal force applied to a brake pedal by a vehicle operator.
Furthermore, the invention provides a controller controlling the opening of at least one air inlet valve responsive to the brake force sensed by a brake pedal sensor 150. According to an aspect, the clutch disengagement rate increases as a function of applied brake pedal force.
According to another aspect, the rate of said clutch disengagement is divided into a first disengagement sequence, wherein the rate is controlled to be as high as possible, a second disengagement sequence, wherein the rate is controlled responsive to the force applied to the brake pedal, and a third clutch disengagement sequence, wherein the rate is controlled to be as fast as possible. This aspect is beneficial since it reduces the time from fully engaged to fully disengaged clutch without sacrificing clutch disengagement smoothness.